UMC makes first 45nm memory chips

The ICs were made using sophisticated immersion lithography for its 12 critical layers, incorporating the latest technology advancements.

Immersion lithography is a resolution enhancement technique that interposes a liquid medium between the scanner optics and the wafer surface, replacing the traditional air gap.

The optical resolution is enhanced since the immersion fluid, which has a higher refractive index than air, allows using lenses with a higher numerical aperture. The result is more accurate patterns imprinted on the silicon wafer.